Preparation method for novel hafnium-silicon-tantalum-oxygen-nitrogen high-dielectric-constant gate dielectric

The invention relates to a preparation method for a novel hafnium-silicon-tantalum-oxygen-nitrogen (HfSiTaON) high-dielectric-constant gate dielectric. The preparation method is characterized by comprising the steps of cleaning a silicon wafer, and then oxidizing the cleaned silicon wafer before deposition; depositing a tantalum pentoxide (Ta O ), silicon oxide (SiO ) and hafnium-oxygen-nitrogen (HfON) laminated gate dielectric on the oxidized silicon wafer, wherein Ta O is positioned on the upper and lower interface of the laminated gate dielectric; SiO is positioned between HfON and Ta O ; carrying out ultrasonic washing on the silicon wafer after the laminated gate dielectric is deposited; then carrying out deposition on the cleaned silicon wafer and annealing to form the hafnium-silicon-tantalum-oxygen-nitrogen (HfSiTaON) high-dielectric-constant gate dielectric; forming a metal gate on the annealed silicon wafer; and sputtering aluminum and alloy on the back surface. According to the preparation method,